This invention was made with Government support under contract. The Government has certain rights in this invention.
This invention relates generally to deposition processes and, more particularly, to techniques for coating insulated wires for use in a space environment. A common problem in spacecraft structures, such as solar panels, is the build-up of electrostatic charge. Uncontrolled discharge of the build-up can damage electronic and other components. Electrostatic discharge (ESD) protection is, therefore, a significant consideration in spacecraft design. Typically, ESD protection takes the form of a conductive coating that effects continuous electrostatic discharge and avoids build up of charge on sensitive components. For solar panels, this ESD protection coating may be a silicon coating with the desired resistivity.
With the development of multi-junction solar cells, where each cell has multiple photovoltaic cells at different levels in the cell structure, the problem of ESD has been has become and even greater concern because multi-junction cells have a higher sensitivity to ESD. Moreover, it has become apparent that there is also a need to provide ESD protection for insulated hookup wires connecting multiple solar cells in a solar cell array or panel. To some degree, electrostatic charge buildup can occur in the wires as well as on the panel itself. Prior to this invention, solar panel hookup wires have been insulated with a polyimide material, such as Kapton, which, as an insulator, provides no significant ESD protection, and is totally inadequate for protection of wiring for multi-junction solar panels. Accordingly, there is still a need to provide ESD protection for insulated wires, as used in solar panel interconnections. The present invention is directed to this end.